Electronic devices such as small hearing devices worn at or in the ear are becoming increasingly sophisticated. Typically such devices include a plurality of integrated circuits which need to exchange different types of data, for instance event-based control information as well as real-time data streams conveying audio signals. Commonly every data type is communicated via a dedicated bus, thus requiring multiple wires between the components. The number of wires interconnecting the components is especially critical for small devices such as hearing devices which need to fit behind an ear or even into an ear canal. State of the art hearing devices for instance commonly employ the following types of standard serial buses:                I2C (Inter-Integrated Circuit) for control data, requiring two wires for data and clock;        SPI (Serial Peripheral Interface) also for control data, requiring three wires for data, clock and one chip select wire for each slave unit connected to the bus;        I2S (Inter-IC Sound) for digital audio data, requiring at least three wires for transmission of up to two audio data channels in one direction and at least four wires for bi-directional transmission; and        S/PDIF (Sony/Philips Digital Interconnect Format) also for digital audio data, based on one wire used for the transmission of up to two audio channels in one direction, so that two wires are needed to provide bi-directional transmission.        
Besides size constrains small portable electronic devices such as hearing devices are typically battery-operated. This imposes stringent power efficiency requirements also on the communication infrastructure within the devices. The standard buses listed above, especially for audio transmission, are not optimised in this respect.